The methods and devices presently utilized for measuring flow rates of components of a fluid stream are generally very complex and yield unreliable results. Some of these systems involve the measurement of two different physical parameters, such as velocity of sound and gamma radiation, while others utilize a more mechanical approach through the use of variable pitch blades which automatically adjust as a function of the fluid density being transferred.
Various equipment units are also in use which are directed toward stratifying the petroleum stream by having it flow at a predetermined angle to the horizontal, such as the device disclosed in U.S. Pat. No. 4,760,742. In this separation and measurement system the stratified stream flows into a gas trap from which the liquid exits by means of a liquid exit pipe. Gas and liquid flow rates are then individually measured by metering devices located downstream from each respective fluid stream. Other separation systems, like that disclosed in U.S. Pat. No. 4,860,591, depend solely on a gravity separation process by subjecting the gas-liquid mixture to a vortical flow motion within an enclosure. Such systems utilize an incoming flow which is internally tangent to the vortex enclosure while exit flow is radial through a porous wall, thereby causing a redirection of the flow and a diminishing of the vortex energy, and further requiring a percolation of the gas component through the liquid as a separation process.